<template>
  <div id="dataCenter">
    <div class="window" @mouseover="stop" @mouseleave="play">
      <ul class="container" :style="containerStyle">
        <li>
          <!-- 把最后一张图放在最开始 -->
          <img :style="{width:imgWidth+'px'}" :src="sliders[sliders.length - 1].img" alt="">
        </li>
        <li  v-for="(item, index) in sliders" :key="index">
          <img :style="{width:imgWidth+'px'}" :src="item.img" alt="" @click="amplification(index)">
        </li>
        <li>
          <!-- 把第一张图放在最后 -->
          <img :style="{width:imgWidth+'px'}" :src="sliders[0].img" alt="">
        </li>
      </ul>
      // 左右切换按钮
      <ul class="direction">
        <li class="left" @click="move(imgWidth, 1, speed)">
          <svg class="icon" width="30px" height="30.00px" viewBox="0 0 1024 1024" version="1.1" xmlns="http://www.w3.org/2000/svg"><path fill="#ffffff" d="M481.233 904c8.189 0 16.379-3.124 22.628-9.372 12.496-12.497 12.496-32.759 0-45.256L166.488 512l337.373-337.373c12.496-12.497 12.496-32.758 0-45.255-12.498-12.497-32.758-12.497-45.256 0l-360 360c-12.496 12.497-12.496 32.758 0 45.255l360 360c6.249 6.249 14.439 9.373 22.628 9.373z"  /></svg>
        </li>
        <li class="right" @click="move(imgWidth, -1, speed)">
          <svg class="icon" width="30px" height="30.00px" viewBox="0 0 1024 1024" version="1.1" xmlns="http://www.w3.org/2000/svg"><path fill="#ffffff" d="M557.179 904c-8.189 0-16.379-3.124-22.628-9.372-12.496-12.497-12.496-32.759 0-45.256L871.924 512 534.551 174.627c-12.496-12.497-12.496-32.758 0-45.255 12.498-12.497 32.758-12.497 45.256 0l360 360c12.496 12.497 12.496 32.758 0 45.255l-360 360c-6.249 6.249-14.439 9.373-22.628 9.373z"  /></svg>
        </li>
      </ul>
      // 小圆点
      <ul class="dots">
        <li v-for="(dot, i) in sliders" :key="i"
            :class="{dotted: i === (currentIndex-1)}"
            @click = jump(i+1)
        >
        </li>
      </ul>
    </div>
    // 点击图片预览
    <div class="mask-div" @click="maskFun()" v-if="maskBol">
      <img :style="{width:imgWidth+'px'}" :src="sliders[imgNumber].img" alt="" class="mask-img">
    </div>
    <iframe src="http://www.gov.cn/zhengce/pdfFile/2021_PDF.pdf" frameborder="0" class="pdf-frame"></iframe>
  </div>
</template>

<script>
export default {
  name: "lunbotu",
  props: {
    initialSpeed: {
      type: Number,
      default: 20
    }, // 图片移动速度
    initialInterval: {
      type: Number,
      default: 1
    } // 如果是一个组件 接受外部传入的切换周期
  },
  data () {
    return {
      sliders: [
        {
          img: 'http://img.hb.aicdn.com/adbde61e4343dedd21e97ea7f22666825a8db7d077ffe-qn8Pjn_fw658'
        },
        {
          img: 'http://img.hb.aicdn.com/adeed7d28df6e776c2fa6032579c697381d1a82b7fe00-fwRqgn_fw658'
        },
        {
          img: 'http://img.hb.aicdn.com/ab7f48509b3c0353017d9a85ef1d12400c9b2724540d4-p3zouo_fw658'
        },
        {
          img: 'http://img.hb.aicdn.com/60f788fc2a846192f224b9e6d4904b30e54926211d3d67-ACFJ9G_fw658'
        },
        {
          img: 'http://img.hb.aicdn.com/22ded455284aab361b8d2056e82f74a891a019704296a-PSraEB_fw658'
        },
        {
          img: 'http://img.hb.aicdn.com/22ded455284aab361b8d2056e82f74a891a019704296a-PSraEB_fw658'
        },
        {
          img: 'http://img.hb.aicdn.com/22ded455284aab361b8d2056e82f74a891a019704296a-PSraEB_fw658'
        }
      ], // 放图片的数组
      imgWidth: 600, // 图片宽度
      currentIndex: 1, // 原点起始位置
      distance: -600, // 外层嵌套的初始移动距离
      transitionEnd: true, // 防止多次快速点击切换出现问题的闸门
      speed: this.initialSpeed,
      timer: null, // 定时器
      imgNumber: 0, // 点击放大的图片
      maskBol: false
    }
  },
  computed: {
    containerStyle () {
      return {
        transform: `translate3d(${this.distance}px, 0, 0)`
      }
    },
    interval () {
      return this.initialInterval * 1000
    }
  },
  created () {
    this.init()
  },
  methods: {
    init () {
      this.play()
    },
    move (offset, direction, speed) { // 移动一次的距离， 向左还是向右移动， 图片移动速度
      if (!this.transitionEnd) return
      this.transitionEnd = false
      direction === -1 ? this.currentIndex += offset / this.imgWidth : this.currentIndex -= offset / this.imgWidth
      if (this.currentIndex > this.sliders.length) this.currentIndex = 1
      if (this.currentIndex < 1) this.currentIndex = this.sliders.length

      const destination = this.distance + offset * direction
      this.animate(destination, direction, speed)
    },
    animate (des, direc, speed) { // 实际移动距离 想左还是向右 移动速度 负右正左
      if (this.temp) {
        window.clearInterval(this.temp)
        this.temp = null
      }
      this.temp = window.setInterval(() => {
        if ((direc === -1 && des < this.distance) || (direc === 1 && des > this.distance)) {
          this.distance += speed * direc
        } else {
          this.transitionEnd = true
          window.clearInterval(this.temp)
          this.distance = des
          let allWidth = this.sliders.length * this.imgWidth
          if (des < -allWidth) this.distance = -this.imgWidth
          if (des > -this.imgWidth) this.distance = -allWidth
        }
      }, 10)
    },
    jump (index) {
      const direction = index - this.currentIndex >= 0 ? -1 : 1
      const offset = Math.abs(index - this.currentIndex) * this.imgWidth
      const jumpSpeed = Math.abs(index - this.currentIndex) === 0 ? this.speed : Math.abs(index - this.currentIndex) * this.speed
      this.move(offset, direction, jumpSpeed)
    },
    // 自动播放函数
    play () {
      if (!this.maskBol) {
        if (this.timer) {
          window.clearInterval(this.timer)
          this.timer = null
        }
        this.timer = window.setInterval(() => {
          this.move(this.imgWidth, -1, this.speed)
        }, this.interval)
      }
    },
    stop () {
      window.clearInterval(this.timer)
      this.timer = null
    },
    amplification (index) {
      this.imgNumber = index
      this.maskBol = true
      this.stop()
    },
    maskFun () {
      this.maskBol = false
      this.play()
    }
  }
}
</script>

<style lang="scss">
*{
  box-sizing: border-box;
  margin:0;
  padding:0;
}
ol,ul{
  list-style: none;
}
#dataCenter{
  text-align: center;
  .window{
    position:relative;
    width:600px;
    height:400px;
    margin:0 auto;
    overflow:hidden;
    .container{
      display:flex;
      position:absolute;
    }
    .left, .right{
      position:absolute;
      top:50%;
      transform:translateY(-50%);
      width:50px;
      height:50px;
      background-color:rgba(0,0,0,.3);
      border-radius:50%;
      cursor:pointer;
    }
    .left{
      left:3%;
      padding-left:12px;
      padding-top:10px;
    }
    .right{
      right:3%;
      padding-right:12px;
      padding-top:10px;
    }
    img{
      user-select: none;
    }
  }
  .dots{
    position:absolute;
    bottom:10px;
    left:50%;
    transform:translateX(-50%);
  }
  .dots li{
    display:inline-block;
    width:15px;
    height:15px;
    margin:0 3px;
    border:1px solid white;
    border-radius:50%;
    background-color:#333;
    cursor:pointer;
  }
  .dots .dotted{
    background-color:orange;
  }
  .mask-div{
    width: 100vw;
    height: 100vh;
    background-color: rgba(0,0,0,.7);
    position: fixed;
    top: 0;
    left: 0;
    .mask-img{
      margin-top: calc(50vh - 200px);
    }
  }
}

.pdf-frame{
  width: 100%;
  height: 70%;
}
</style>
